UCLA has been NIH funded as a Pediatric AIDS Clinical Trials Unit for Los Angeles since its inception in1988 and as a HIV Prevention Trials Unit for Brazil since 2000. We propose the UCLA LA/BRAZIL AIDS consortium CTU (UCLA-LABAC-CTU) with 5 domestic sites in LA participating as a consortium affiliated with IMPAACT and 5 Brazilian sites participating in multiple networks (IMPAACT, HPTN and AACTG). The proposed UCLA CTU-affiliated clinical sites were chosen as preferred sites by the respective networks (IMPAACT, HPTN, AACTG) by independent reviewers and network leadership. Our specific aims include enrolling significant numbers of HIV infected and at risk infants, children, adolescents and adults into high priority clinical trials associated with NIH networks, contributing to the NIH scientific agenda, maintaining administrative and financial, scientific and data, regulatory and laboratory oversight of affiliated CRS and maintaining and expanding our community outreach and CAB. The LA consortium includes UCLA, Long Beach Memorial, Harbor-UCLA, Children's Hospital LA and Children's Hospital Orange County. This consortium is the major catchment area for geographically and ethnically diverse population (>1000 HIV-exposed / infected children / adolescents and >150 HIV-infected pregnant women/year. UCLA has functioned as the main administrative, data entry, laboratory, CAB and mentor for the group. This resulted insignificant success in clinical trials experience and economic efficiency. Since 1989 we unrolled 826 patients in 71 phase I, II &III perinatal pediatric HIV trials, with excellent retention, data quality and publication records. In Brazil, our group includes HSE hospital in Rio, 3 sites in Porto Alegre, (Concoicao, Santa Casa and Femina Hospitals), and 1 in Sao Paulo (Federal University). All are established UCLA-HPTN sites and 2are also PACTG and AACTG sites. These sites have enrolled >900 subjects in clinical trials (265 enrolled inHPTN040 MTCT). Five other NIH-sponsored trials are being initiated this year. All Brazil CRS propose affiliation with IMPAACT and 2 with the AACTG and HPTN. These sites care for 1700 HIV infected children,900 adolescents, 800 pregnant women, and the AACTG sites have 4,700 infected adults and access to large cohorts of at risk seronegative adults. The LABAC CTU and CRS are successful units with the infrastructure and experience needed for the conduct of both complex and multicenter NIH Network trials. ADMINISTRATIVE COMPONENT: